Bell's a dark horse to be the starting LG this year. He doesn't get a lot of the attention, and he's not getting the first shot, but he's started more games in this league (72) than the other candidates (Cooper, 14 or Green, 2), and he's been more or less healthy when he's been in the lineup. If he gets in shape, just staying in the lineup might make him more valuable than either Green or Cooper, who've had their struggles staying available.
On a side note, I wonder what weight they want him to get down to. If he's 320 now. Cooper's listed as 310, and Green 314. Bell is taller than both of those guys. If he's got two more cut downs to make, he'll be pretty skinny for an NFL OL...